Various devices serve, at least in part, to process signals that are bounded, one way or the other, by a given bandwidth. In many cases this is done to ensure that the signal fits within some limited processing capability as corresponds to the processing platform and/or the application setting. For example, some processing platforms (such as cellular telephones) often limit the audio signal to be processed to some predetermined bandwidth such as 300 to 3,400 Hz even though the original speech content may include frequencies that are outside that range.
In recognition of the fact that such constraints can limit sound quality, some platforms further process such a signal using artificial bandwidth extension. Generally speaking, artificial bandwidth extension typically comprises adding artificially generated content outside the aforementioned predetermined bandwidth to the processed signal in order to hopefully improve the resultant sound quality.
Unfortunately, the success of such an approach can itself be quite arbitrary and unpredictable. In some cases, the corresponding result can be natural sounding and relatively pleasing to the listener. In other cases, however, the bandwidth extended result can be quite unnatural and unpleasant. At worst, the introduction of this artificially generated content can make it more difficult to discern the substantive content of the original audio content.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary technical meaning as is accorded to such terms and expressions by persons skilled in the technical field as set forth above except where different specific meanings have otherwise been set forth herein.